It is sometimes assumed that feminist art—the art made in the heyday of feminism’s second wave in the 1960s and ’70s—was monolithic. Nothing could be further from the truth. While there was general agreement about the existence of gender disparities, artists, like activists, differed widely in how they addressed them. Just as there were and are many feminisms, there were and are many branches of feminist art.

Even today, one of the most fractious issues within feminist political and artistic circles is the question of pornography and the politics of erotic representation. While much feminist art has been integrated into mainstream art history, artists who embraced a sex-positive attitude in their work have been systematically excluded from important exhibitions and catalogues devoted to women’s art. This subset—what I like to call the “black sheep” feminist artists—were in some cases actively subjected to censure in the ’70s. They are still largely overlooked within the legacy of feminist art as a whole. Artists like Anita Steckel, Betty Tompkins, Joan Semmel, and Cosey Fanni Tutti explored the extreme edges of feminist politics and sexualized iconography; for this reason, their work remains marginalized.

In 1973, Semmel joined Steckel’s newly formed Fight Censorship (FC) group. (Steckel, whose work is completely overlooked today, may be best known as a political organizer.) In a 1973 press release, the collective described itself as “women artists who have done, will do, or do some form of sexually explicit art, i.e., political, humorous, erotic, psychological.” Under the banner “Women Artists Join to Fight to Put Sex into Museums and Get Sexism and Puritanism Out,” Semmel and her FC colleagues attempted to create a context for their practices, and pushed for wider acceptance of sexually explicit artworks by women. One of the things that made these artists controversial was their handling of the male body. As scholar Richard Meyer has written, they “eroticized the male body in ways that conformed neither to heterosexual convention nor to mainstream feminist thought at the time….The art they produced reminds us that sexuality cannot be made to align with politics, including the politics of feminism.” In a 2007 interview with Meyer, Semmel said that she was trying “to find an erotic language to which women could respond, one which did not reiterate the male power positions and prevalent fetishizations in conventional pornography and art.” She “wanted to develop a language whereby a woman could express her own desires, whatever they might be, without shame or sentimentality.”

Cosey Fanni Tutti is best known as a cult figure in the UK. From 1973 to 1980, she exploded the comparatively tame conventions of “feminist” body and performance art by completely immersing herself as a model in the pornographic magazine business. Without announcing herself as an artist or delimiting the terms of her work as a “performance”—thereby depriving herself of the safety net of “art”—she posed in over 40 magazine “actions.” Since her famously censored show at the Institute of Contemporary Art in London, in 1976, Cosey Fanni Tutti remains relatively unknown in international circles.

Even within this sex-positive black-sheep subset of feminist art, there were conceptual and political rifts. Unlike Semmel, whose paintings were based on photographs of models taken in her studio, Tompkins culled the subject matter for her monumental, photorealistic “Fuck Paintings”—tightly cropped scenes of heterosexual penetration—from hardcore pornographic photographs and, later, porn magazines, which were illegal in the United States at the time. Semmel objected to Tompkins’s appropriation of these images on the grounds that they form an exploitative, misogynist industry, and could not be redeemed, even through their cooption by a woman artist.

As contemporary debates about pornography rage on—can it be empowering to women or it is always exploitation?—it seems these artists’ time has come: recently, Semmel and Tompkins have gotten renewed attention, through exhibitions. Perhaps now we can acknowledge that their approach is one of the more radical contributions to recent art history.

While these women continue to be the black sheep who strayed from the established feminist flock, today they provide essential performative, discursive, and iconographic precedents for a host of contemporary art practices that explore hardcore, sex-positive terrain—from Jeff Koons’s “Made in Heaven” series to more recent porn-inspired work by John Currin. Despite being shut out of the mainstream canon of “feminist” art, these four artists represent the unsung matriarchal forebears for those artists who seek to push the limits of body art, political correctness, and (female) sexual agency.

Alison M. Gingeras is adjunct curator at Dallas Contemporary in Dallas, Texas. Her exhibition “Black Sheep Feminism: The Art of Sexual Politics” will run from January 23 to March 18, 2016.

A version of this story originally appeared in the June 2015 issue of ARTnews on page 66 under the title “Black-Sheep Feminists.”